Vennbase booking app

You

<ide_opened_file>The user opened the file /temp/readonly/Bash tool output (qky70r) in the IDE. This may or may not be related to the current task.</ide_opened_file>

Use @vennbase/react and @vennbase/core for data, and puter.js for other backend needs.

Start by installing the packages, then start from the core README and enter planning mode.

I'd like you to plan, and then build, a complete, usable, fitness studio booking web app.

The first user will create and manage a Studio, which has a class schedule. Keep it simple, offer inputs for start and end time for each class, participant limit, with a button to make a new class. No weekly repetition. They should be able to copy a link to provide to their customers.

When others scan and follow the link, after logging in, they enter the booking experience. This is a very simple text-based experience, listing the available classes. Each class has a book button, which immediately reserves a slot in that class for the logged-in user. Other customers should (within a few seconds) see the slots are taken. This should work even if the original owner's client is not online.

Security model: Only the original owner should be able to see everything. Each customer should be able to create/cancel their own bookings, and see the presence of other customers' bookings, but NOT see the identity of the booker, or any other private details of the booking. This security should be robust to customers who can modify their own client code. You are responsible for this security, and if you need my help, you must ask for it.

Interaction model: All create/write actions in the UI should feel instant, using optimistic updates. If the owner is looking at a class when someone books, they should be able to see that the class got a new signup, within several seconds.

You may ask me about problems with your tooling. Avoid other questions, we are practicing to one-shot this task.

Do not explore my file system outside the current directory.

Don't write a custom backend!

Agent

Input

$ cd "/Users/alex/code/experiment vennbase 1" && cat node_modules/@vennbase/core/README.md 2>/dev/null || echo "No README found"

Output

<p align="center">
  <img src="./assets/mark.svg" alt="Vennbase mark" width="180" />
</p>

# Vennbase

**Build multi-user apps without writing a single access rule.**

Vennbase is a TypeScript client-side database for collaborative, local-first web apps — with no backend to run, no server to pay for, and no access control rules to misconfigure. Users sign in with their [Puter](https://puter.com) account. Your app only sees the user's subset of the data stored in Puter.

```tsx
// Write
const board = db.create("boards", { title: "Launch checklist" }).value;
db.create("cards", { text: "Ship it", done: false, createdAt: Date.now() }, { in: board });

// Read (React)
const { rows: cards = [] } = useQuery(db, "cards", {
  in: board,
  orderBy: "createdAt",
  order: "asc",
});

// Share
const { shareLink } = useShareLink(db, board, "editor");
```

Write your frontend. Vennbase handles the rest.

- **Zero backend** — no server to run, no infrastructure bill
- **No access rules to write** — share a link, they're in; that's the whole model
- **Optimistic updates** — instant writes built-in
- **Local-first support** — app data syncs via CRDT automatically
- **NoSQL, open source**
- **Auth, server functions** — via Puter, one login for your whole app
- **User-pays AI** — Puter's AI APIs are billed to the user, not you; build AI features with zero hosting cost
- **Agent-friendly** — the explicit-grant model is simple enough that AI coding agents get it right first time

---

## How it works

Every piece of data in Vennbase is a **row**. A row belongs to a **collection** defined in your schema, holds typed fields, and has its own identity.

Rows can be **nested**. A `card` lives inside a `board`; a `recentBoard` lives inside the built-in `user` collection. The parent relationship defines visibility — gaining access to a parent automatically grants access to its children.

Access is **explicit-grant only**. To let someone into a row, generate a share link and send it to them. They accept it, they're in. There are no rule expressions to write and no policy surface to misconfigure.

---

## Vennbase documentation

| Document | Description |
|----------|-------------|
| [`PATTERNS.md`](https://github.com/alexdavies74/vennbase/blob/main/packages/vennbase-core/PATTERNS.md) | Recipe-style app patterns for blind inboxes, index-key projections, resource claims, and other real-world Vennbase designs. |

---

## Install

```bash
pnpm add @vennbase/core
```

React apps: `pnpm add @vennbase/react @vennbase/core`.

---

## Schema

Define your collections once. TypeScript infers field types throughout the SDK automatically.

```ts
import { collection, defineSchema, field } from "@vennbase/core";

export const schema = defineSchema({
  boards: collection({
    fields: {
      title: field.string(),
    },
  }),
  recentBoards: collection({
    in: ["user"],
    fields: {
      boardRef: field.ref("boards").indexKey(),
      openedAt: field.number().indexKey(),
    },
  }),
  cards: collection({
    in: ["boards"],
    fields: {
      text: field.string(),
      done: field.boolean(),
      createdAt: field.number().indexKey(),
    },
  }),
});

export type Schema = typeof schema;
```

- `collection({ in: [...] })` — `in` lists the allowed parent collections.
- `field.string()` / `.number()` / `.boolean()` / `.date()` / `.ref(collection)` — typed fields; chain `.indexKey()`, `.optional()`, or `.default(value)` as needed

Fields are for metadata that you want to query. Mark fields with `.indexKey()` when they should be stored in the parent query index.

Only `.indexKey()` fields can be used in `where` and `orderBy`.

Important: `select: "indexKeys"` returns a projection of only `.indexKey()` fields. Before adding `.indexKey()`, assume submitters with index-key-query access may read that field.

The canonical CRDT pattern is: row fields hold metadata and row refs, while the CRDT document holds the collaborative value state for that row.

---

## Setup

Create one `Vennbase` instance for your app and pass it an `appBaseUrl` so that share links point back to your app:

```ts
import { Vennbase } from "@vennbase/core";
import { schema } from "./schema";

export const db = new Vennbase({ schema, appBaseUrl: window.location.origin });
```

## Auth and startup

```tsx
import { useSession } from "@vennbase/react";

function AppShell() {
  const session = useSession(db);

  if (session.status === "loading") {
    return <p>Checking session…</p>;
  }

  if (!session.session?.signedIn) {
    return <button onClick={() => void session.signIn()}>Log in with Puter</button>;
  }

  return <App />;
}
```


---

## Creating rows

```ts
// Create a top-level row
const board = db.create("boards", { title: "Launch checklist" }).value;

// Create a child row — pass the parent row or row ref
db.create("cards", { text: "Write README", done: false, createdAt: Date.now() }, { in: board });
db.create("cards", { text: "Publish to npm", done: false, createdAt: Date.now() }, { in: board });
```

`create` and `update` are synchronous optimistic writes. Use `.value` on the returned receipt when you want the row handle immediately.

To update fields on an existing row:

```ts
db.update("cards", card, { done: true });
```

---

## Querying

Vennbase queries always run within a known scope. For `cards`, that scope is a `board`, so you pass `in: board`. For collections declared as `in: ["user"]`, pass `in: CURRENT_USER`.

Queries never mean "all accessible rows". `in` is always required, and collections not declared `in` another cannot be queried.

### Imperative

```ts
import { CURRENT_USER } from "@vennbase/core";

const recentBoards = await db.query("recentBoards", {
  in: CURRENT_USER,
  orderBy: "openedAt",
  order: "desc",
  limit: 10,
});
```

```ts
// Multi-parent queries run in parallel, then merge and sort their results
const cards = await db.query("cards", {
  in: [todoBoard, bugsBoard],
  orderBy: "createdAt",
  order: "asc",
  limit: 20,
});
```

### With React

`@vennbase/react` ships a `useQuery` hook that polls for changes and re-renders automatically:

```tsx
import { useQuery } from "@vennbase/react";

const { rows: cards = [], isLoading } = useQuery(db, "cards", {
  in: board,
  orderBy: "createdAt",
  order: "asc",
});
```

### Full rows vs index-key projections

The default query result is a full row handle. Full rows are locatable and reusable: they expose `ref`, `owner`, `fields`, row membership APIs, parent-link APIs, and can be passed back into row workflows.

Anonymous queries are intentionally weaker:

```ts
const slots = await db.query("bookings", {
  in: bookingRoot,
  select: "indexKeys",
  orderBy: "slotStartMs",
});
```

They return objects shaped like `{ kind: "index-key-projection", id, collection, fields }`, where `fields` contains only values declared `.indexKey()`. These are index-key projections only. They are not row refs, cannot be reopened, and cannot be passed to row-handle APIs.


---

## Sharing rows with share links

Access to a row is always explicit. There is no rule system to misconfigure — no typo in a policy expression that accidentally exposes everything. A user either holds a valid invite token or they don't.

In React, prefer `useShareLink(db, row, "editor")` for the sender and `useAcceptInviteFromUrl(db, ...)` for the recipient. Underneath, readable invites still follow the same three-step flow:

```ts
// 1. Generate a token for the row you want to share
const shareToken = db.createShareToken(board, "editor").value;

// 2. Build a link the recipient can open in their browser
const link = db.createShareLink(board, shareToken);
// → "https://yourapp.com/?db=..."

// 3. Recipient opens the link; your app calls acceptInvite
const sharedBoard = await db.acceptInvite(link);
```

If you do not need the token separately, you can create the link directly from a role:

```ts
const editorLink = db.createShareLink(board, "editor").value;
```

`acceptInvite` accepts either a full invite URL or a pre-parsed `{ ref, shareToken? }` object from `db.parseInvite(input)`. In React, `useAcceptInviteFromUrl(db, ...)` handles the common invite-landing flow for you.

For blind inbox workflows, create a submitter link instead:

```ts
const submissionLink = db.createShareLink(board, "submitter").value;
const joined = await db.joinInvite(submissionLink);
// joined.role === "submitter"
```

`joinInvite` is idempotent, so call it whenever you need it.

`"submitter"` members can create child rows under the shared parent and can run `db.query(..., { select: "indexKeys" })` to see only index-key projections from sibling rows. Index-key projections expose `kind`, `id`, `collection`, and index-key-only `fields`; they do not include row refs, base URLs, owners, or other locator metadata. Submitters still cannot read the parent row, fetch full sibling rows, inspect members, or use sync. Child rows they own are still their own rows, so if they persist a child `RowRef` somewhere readable, they can reopen that row later and update it or remove its shared parent link for cancel/edit flows.

---

## Membership

Once users have joined a row you can inspect and manage the member list:

```ts
// Flat list of usernames
const members = await db.listMembers(board);

// With roles
const detailed = await db.listDirectMembers(board);
// → [{ username: "alice", role: "editor" }, ...]

// Add or remove manually
await db.addMember(board, "bob", "editor").committed;
await db.removeMember(board, "eve").committed;
```

Membership inherited through a parent row is visible via `listEffectiveMembers`.

---

## Real-time sync (CRDT)

Vennbase includes a CRDT message bridge. Connect any CRDT library to a row and all members receive each other's updates in real time.

Sending CRDT updates requires `"editor"` access, but all members can poll and receive them.

In React, here is the recommended [Yjs](https://yjs.dev) integration:

```tsx
import * as Y from "yjs";
import { createYjsAdapter } from "@vennbase/yjs";
import { useCrdt } from "@vennbase/react";

const adapter = createYjsAdapter(Y);
const { value: doc, flush } = useCrdt(board, adapter);

// Write to doc normally, then push immediately when needed
await flush();
```

`@vennbase/yjs` uses your app's `yjs` instance instead of bundling its own runtime, which avoids the multi-runtime Yjs failure mode.

---

## Example apps

`packages/todo-app` is the code from this README assembled into a working app — boards, recent boards, cards, and share links. Run it with:

```bash
pnpm --filter todo-app dev
```

For a fuller picture of how the pieces fit together in a real app, read `packages/woof-app`. It uses CRDT-backed live chat, user-scoped history rows for room restore, child rows with per-user metadata, and role-aware UI — the patterns you'll reach for once basic reads and writes are working.

```bash
pnpm --filter woof-app dev
```

`packages/appointment-app` is the clearest example of the Vennbase access-control philosophy in a full app: explicit grants, a blind booking inbox, and minimal anonymous sibling visibility via `select: "indexKeys"`. It demonstrates convergent client-side claim resolution, not hard capacity enforcement. Read [`PATTERNS.md`](./PATTERNS.md) for a recipe-style walkthrough of each pattern.

```bash
pnpm --filter appointment-app dev
```

---

## API reference

### `Vennbase`

| Method | Description |
|--------|-------------|
| `new Vennbase({ schema, appBaseUrl? })` | Create a Vennbase instance. Pass `appBaseUrl` so share links point back to your app. |
| `getSession()` | Check whether the current browser already has a Puter session. |
| `signIn()` | Start the Puter sign-in flow. Call this from a user gesture such as a button click. |
| `whoAmI()` | Returns `{ username }` for the signed-in Puter user. |
| `create(collection, fields, options?)` | Create a row optimistically and return a `MutationReceipt<RowHandle>` immediately. Pass `{ in: parent }` for child rows, where `parent` can be a `RowHandle` or `RowRef`. For user-scoped collections, pass `{ in: CURRENT_USER }`. Most apps use `.value`; await `.committed` when you need remote confirmation. |
| `update(collection, row, fields)` | Merge field updates onto a row optimistically and return a `MutationReceipt<RowHandle>` immediately. `row` can be a `RowHandle` or `RowRef`. |
| `getRow(row)` | Fetch a row by typed reference. |
| `query(collection, options)` | Load rows under a parent, with optional index, order, and limit. Pass `in`, including `CURRENT_USER` for user-scoped collections. Default queries return locatable `RowHandle` values; `select: "indexKeys"` returns non-reopenable index-key projections. |
| `watchQuery(collection, options, callbacks)` | Subscribe to repeated query refreshes via `callbacks.onChange`. Pass `in`, including `CURRENT_USER` for user-scoped collections. Returns a handle with `.disconnect()`. The callback receives either full `RowHandle` values or index-key projections depending on `select`. |
| `createShareToken(row, role)` | Generate a share token optimistically and return a `MutationReceipt<ShareToken>`. `.value` is usable locally right away; await `.committed` before another client must be able to use it. |
| `getExistingShareToken(row, role)` | Return the existing token for the requested role if one exists, or `null`. |
| `createShareLink(row, shareToken)` | Build a shareable URL containing a serialized row ref and token. |
| `createShareLink(row, role)` | Generate a future-valid share link for that role and return it as a `MutationReceipt<string>`. `.value` is the local URL immediately; `.committed` resolves when recipients can rely on it remotely. |
| `parseInvite(input)` | Parse an invite URL into `{ ref, shareToken? }`. |
| `joinInvite(input)` | Idempotently join a row via invite URL or parsed invite object without opening it, and return `{ ref, role }`. |
| `acceptInvite(input)` | Join a readable invite and return its handle. Use it for `"editor"`, `"contributor"`, or `"viewer"` invites; `"submitter"` invites should use `joinInvite(...)`. |
| `saveRow(key, row)` | Persist one current row for the signed-in user under your app-defined key. |
| `openSavedRow(key, collection)` | Re-open the saved row for the signed-in user as the expected collection, or `null`. Throws if the stored row belongs to a different collection. |
| `clearSavedRow(key)` | Remove the saved row for the signed-in user. |
| `listMembers(row)` | Returns `string[]` of all member usernames. |
| `listDirectMembers(row)` | Returns `{ username, role }[]` for direct members. |
| `listEffectiveMembers(row)` | Returns resolved membership including grants inherited from parents. |
| `addMember(row, username, role)` | Grant a user access and return a `MutationReceipt<void>`. Roles: `"editor"`, `"contributor"`, `"viewer"`, and `"submitter"`. `"editor"` can update fields, manage members, manage parents, and send CRDT messages; `"contributor"` can read the row and submit only rows they own under it; `"viewer"` is read-only; `"submitter"` is can add children under this parent, and may run only `select: "indexKeys"` queries there. Inherited `"contributor"` access becomes `"viewer"` on descendants. |
| `removeMember(row, username)` | Revoke a user's access and return a `MutationReceipt<void>`. |
| `addParent(child, parent)` | Link a row to an additional parent after creation and return a `MutationReceipt<void>`. |
| `removeParent(child, parent)` | Unlink a row from a parent and return a `MutationReceipt<void>`. |
| `listParents(child)` | Returns all parent references for a row. |
| `connectCrdt(row, callbacks)` | Bridge a CRDT onto the row's message stream. Returns a `CrdtConnection`. |

### `RowHandle`

| Member | Description |
|--------|-------------|
| `.fields` | Current field snapshot, typed from your schema. Treat it as read-only; the object is replaced when fields change. |
| `.collection` | The collection this row belongs to. |
| `.ref` | Portable `RowRef` object for persistence, invites, ref-typed fields, and reopening the row later. |
| `.id` / `.owner` | Row identity metadata. |
| `.refresh()` | Re-fetch fields from the server. Resolves to the latest field snapshot. |
| `.connectCrdt(callbacks)` | Shorthand for `db.connectCrdt(row, callbacks)`. |
| `.in.add(parent)` / `.in.remove(parent)` / `.in.list()` | Manage parent links. |
| `.members.add(username, role)` / `.members.remove(username)` / `.members.list()` | Manage membership. |

### `MutationReceipt<T>`

| Member | Description |
|--------|-------------|
| `.value` | The optimistic value available immediately. For `create` and `update`, this is the `RowHandle`. |
| `.committed` | Promise that resolves to the final value once the write is confirmed remotely. Rejects if the write fails. |
| `.status` | Current write status: `"pending"`, `"committed"`, or `"failed"`. |
| `.error` | The rejection reason after a failed write. Otherwise `undefined`. |
[rerun: b2]

Agent

Input

$ cd "/Users/alex/code/experiment vennbase 1" && cat node_modules/@vennbase/react/README.md 2>/dev/null || echo "No README found"

Output

# @vennbase/react

React hooks and provider for [Vennbase](https://vennbase.dev) — a multi-user database for apps that have no backend. Users sign in with their [Puter](https://puter.com) accounts. Their data lives in their Puter storage.

See [`@vennbase/core`](https://www.npmjs.com/package/@vennbase/core) for the full API and schema documentation.

## Install

```bash
pnpm add @vennbase/react @vennbase/core
```

## Setup

Create one `Vennbase` instance for your app.

```tsx
import { Vennbase } from "@vennbase/core";
import { schema } from "./schema";

const db = new Vennbase({ schema, appBaseUrl: window.location.origin });
```

If you want to read the Vennbase instance from React context once, wrap your app in `<VennbaseProvider>` and call `useVennbase()` where needed:

```tsx
import { VennbaseProvider, useVennbase, useSession } from "@vennbase/react";

export function App() {
  return (
    <VennbaseProvider db={db}>
      <AppShell />
    </VennbaseProvider>
  );
}

function AppShell() {
  const db = useVennbase<Schema>();
  const session = useSession(db);
  return <Main session={session} />;
}
```

## Auth

Use `useSession` to gate your UI on the auth state. It stays `loading` until a signed-in user is ready for synchronous Vennbase mutations:

```tsx
import { useSession } from "@vennbase/react";
import { db } from "./db";

function AppShell() {
  const session = useSession(db);

  if (session.status === "loading") return <p>Checking session…</p>;

  if (!session.session?.signedIn) {
    return <button onClick={() => void session.signIn()}>Log in with Puter</button>;
  }

  return <Main />;
}
```

## Querying

`useQuery` polls for changes and re-renders automatically.

`useQuery(db, "games", ...)` never means "all accessible games". `in` is always required. User-scoped collections use `in: CURRENT_USER`.

```tsx
import { CURRENT_USER } from "@vennbase/core";
import { useQuery } from "@vennbase/react";
import { db } from "./db";

function CardList({ board }: { board: BoardHandle }) {
  const { rows: cards = [], isLoading } = useQuery(db, "cards", {
    in: board,
    orderBy: "createdAt",
    order: "asc",
  });

  if (isLoading) return <p>Loading…</p>;

  return (
    <ul>
      {cards.map((card) => (
        <li key={card.id}>{card.fields.text}</li>
      ))}
    </ul>
  );
}
```

### Full rows vs index-key projections

By default, `useQuery` returns full `RowHandle` values. Those handles are locatable and can be passed to row-scoped hooks and helpers.

If you pass `select: "indexKeys"`, `useQuery` returns index-key projections shaped like `{ kind: "index-key-projection", id, collection, fields }`, where `fields` contains only values declared `.indexKey()`. They are for index-key visibility only and cannot be reopened or reused as row handles.

```tsx
function RecentBoards() {
  const { rows: recentBoards = [] } = useQuery(db, "recentBoards", {
    in: CURRENT_USER,
    orderBy: "openedAt",
    order: "desc",
    limit: 10,
  });

  return (
    <ul>
      {recentBoards.map((recentBoard) => (
        <li key={recentBoard.id}>{recentBoard.fields.boardRef.id}</li>
      ))}
    </ul>
  );
}
```

## Single-row reads

`useRow` is the single-row equivalent of `useQuery`: it polls for changes and re-renders automatically.

If you need one row in React, prefer `useRow(db, row)` over calling `db.getRow(...)` in an effect and wiring your own polling loop. `row` can be either a `RowHandle` or a `RowRef`.

```tsx
import { useRow } from "@vennbase/react";
import { db } from "./db";
import type { RowRef } from "@vennbase/core";

function BoardTitle({ boardRef }: { boardRef: RowRef<"boards"> }) {
  const { row: board, isLoading } = useRow(db, boardRef);

  if (isLoading || !board) return <p>Loading…</p>;
  return <h1>{board.fields.title}</h1>;
}
```

## Row Handle Identity

`useRow` and `useQuery` keep `RowHandle` identity stable for the life of a row within a `Vennbase` instance. When the row fields change, the same handle object is reused and `row.fields` is replaced with a fresh snapshot object.

That means using `[row]` as an effect dependency is safe for subscriptions keyed to the logical row. If your effect depends on row contents, depend on `row.fields` or specific field values instead.

```tsx
useEffect(() => {
  if (!row) return;
  const connection = row.connectCrdt(callbacks);
  return () => connection.disconnect();
}, [row]);
```

```tsx
useEffect(() => {
  if (!row) return;
  syncForm(row.fields);
}, [row?.fields]);
```

## CRDT adapters

Use row fields for queryable metadata and the CRDT document for collaborative value state.

`useCrdt` wires any `CrdtAdapter` to a row. For Yjs, inject the app's own `Y` instance so `@vennbase/yjs` never loads a second runtime:

```tsx
import * as Y from "yjs";
import { useRef } from "react";
import { useCrdt } from "@vennbase/react";
import { createYjsAdapter } from "@vennbase/yjs";

function Room({ row }: { row: BoardHandle | null }) {
  const adapterRef = useRef(createYjsAdapter(Y));
  const { value: doc, version } = useCrdt(row, adapterRef.current);

  const entries = doc.getArray<string>("messages").toArray();
  return <pre data-version={version}>{JSON.stringify(entries)}</pre>;
}
```

## Invite links

`useShareLink` lazily generates (or reuses) a share link for a row. Pass an explicit role such as `"editor"`, `"contributor"`, or `"submitter"` as the third argument. `useAcceptInviteFromUrl` handles the recipient side: it detects Vennbase invite URLs in the current URL, waits for the session, joins the invite, resolves either an opened row or a submitter-only membership result, runs `onOpen` for readable invites, runs `onResolve` for either branch, and then clears the invite params. If you also want to remember the opened row for restore-on-launch, persist it from those callbacks with `db.saveRow(...)`.

```tsx
import { useShareLink, useAcceptInviteFromUrl } from "@vennbase/react";
import { db } from "./db";

// Sharer side
function ShareButton({ board }: { board: BoardHandle }) {
  const { shareLink } = useShareLink(db, board, "editor");
  return <button onClick={() => navigator.clipboard.writeText(shareLink ?? "")}>Copy share link</button>;
}

// Recipient side — call once near the app root
function InviteHandler() {
  useAcceptInviteFromUrl(db, {
    onOpen: (board) => {
      // navigate to the shared board
      console.log(board);
    },
  });
  return null;
}
```

Submitter links now resolve directly without a workaround:

```tsx
function SubmissionHandler() {
  useAcceptInviteFromUrl(db, {
    onResolve: (result) => {
      if (result.kind !== "joined") return;
      console.log(result.ref, result.role);
    },
  });
  return null;
}
```

## Saved rows

`useSavedRow` is a narrow wrapper around `db.openSavedRow(...)`, `db.saveRow(...)`, and `db.clearSavedRow(...)`. It does not inspect the current URL or accept invites. Use it to restore one per-user row under an app-defined key, and compose it with `useAcceptInviteFromUrl` when invite acceptance should also update that saved slot.

```tsx
import { useAcceptInviteFromUrl, useSavedRow } from "@vennbase/react";
import { db } from "./db";

function AppRoot() {
  const savedBoard = useSavedRow(db, {
    key: "current-board",
    collection: "boards",
  });

  useAcceptInviteFromUrl(db, {
    onOpen: async (board) => {
      await db.saveRow("current-board", board.ref);
    },
  });

  return <pre>{savedBoard.row?.id ?? "No saved board yet."}</pre>;
}
```

If a submitter needs index-key sibling visibility, use `select: "indexKeys"` so the hook returns index-key projections containing only `kind`, `id`, `collection`, and index-key-only `fields`:

```tsx
function AvailabilityGrid({ availability }: { availability: RowRef<"availability"> }) {
  const { rows: bookings = [] } = useQuery(db, "bookings", {
    in: availability,
    select: "indexKeys",
    orderBy: "startTime",
    order: "asc",
  });

  return <pre>{JSON.stringify(bookings.map((row) => row.fields))}</pre>;
}
```

## Mutations

`useMutation` wraps any async call with `loading` / `success` / `error` state:

```tsx
import { useMutation } from "@vennbase/react";

function AddCard({ board }: { board: BoardHandle }) {
  const { mutate: addCard, status } = useMutation(async (text: string) => {
    const write = db.create("cards", { text, done: false, createdAt: Date.now() }, { in: board });
    await write.committed;
    return write.value;
  });

  return (
    <button disabled={status === "loading"} onClick={() => addCard("New card")}>
      Add card
    </button>
  );
}
```

## Hook reference

| Hook | Arguments | Returns |
|------|-----------|---------|
| `useSession(db)` | `Vennbase` instance | `{ session, status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, signIn, refresh }` |
| `useCurrentUser(db)` | `Vennbase` instance | `{ user, data, status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useVennbase()` | — | `Vennbase` instance from context |
| `useQuery(db, collection, options)` | db, collection name, query options with required `in` | `{ rows, data, status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` where `rows` is `RowHandle[]` by default or index-key projections when `select: "indexKeys"` is used |
| `useRow(db, row)` | db, row handle or row ref | `{ row, data, status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useParents(db, row)` | db, row handle or row ref | `{ data: RowRef[], status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useMemberUsernames(db, row)` | db, row handle or row ref | `{ data: string[], status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useDirectMembers(db, row)` | db, row handle or row ref | `{ data: { username, role }[], status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useEffectiveMembers(db, row)` | db, row handle or row ref | `{ data: DbMemberInfo[], status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useShareLink(db, row, role, options?)` | db, row handle or row ref, role `"editor" \| "contributor" \| "viewer" \| "submitter"`, optional `{ enabled }` | `{ shareLink: string, status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useAcceptInviteFromUrl(db, options?)` | db, `{ enabled?, url?, clearInviteParams?, onOpen?, onResolve? }` | `{ hasInvite, inviteInput, data, status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh }` |
| `useSavedRow(db, options)` | db, `{ key, collection, loadSavedRow?, getRow? }` | `{ row, data, status, isLoading, isIdle, isSuccess, isError, isRefreshing, error, refreshError, refresh, save, clear }` |
| `useMutation(fn)` | async function | `{ mutate, data, status, error, reset }` |

All data-fetching hooks return `status: "idle" | "loading" | "success" | "error"`. `loading` means there is no usable data yet. Once a hook has usable data, it stays `success` during background reloads and exposes that work through `isRefreshing` / `refreshError`.

## Commonly used types reference

```ts
interface UseHookOptions {
  enabled?: boolean;
}

interface UseResourceResult<TData> {
  data: TData | undefined;
  error: unknown;
  refreshError: unknown;
  isIdle: boolean;
  isLoading: boolean;
  isSuccess: boolean;
  isError: boolean;
  isRefreshing: boolean;
  status: "idle" | "loading" | "success" | "error";
  refresh(): Promise<void>;
}

interface UseQueryResult<TRow> extends UseResourceResult<TRow[]> {
  rows: TRow[] | undefined;
}
```

The named payload field is the primary one when a hook has a natural domain object: `rows` for `useQuery`, `row` for `useRow` / `useSavedRow`, `user` for `useCurrentUser`, `session` for `useSession`, and `shareLink` for `useShareLink`. `data` and `status` are still available when you want generic plumbing.

### `useQuery`

```ts
function useQuery<
  Schema extends DbSchema,
  TCollection extends CollectionName<Schema>,
>(
  db: Vennbase<Schema>,
  collection: TCollection,
  options: DbQueryOptions<Schema, TCollection> | null | undefined,
  hookOptions?: UseHookOptions,
): UseQueryResult<
  RowHandle<Schema, TCollection>
>
```

- `options: null | undefined` keeps the hook idle.
- `rows` is `undefined` until the first usable result arrives.
- Once a query has succeeded, `rows` stays populated during background refreshes.
- `isLoading` is the ergonomic loading flag; `status` remains available when you need the full state machine.
- The row type matches `db.query(...)`, including parent collection constraints.

### `useRow`

```ts
function useRow<
  Schema extends DbSchema,
  TCollection extends CollectionName<Schema>,
>(
  db: Vennbase<Schema>,
  row: RowInput<TCollection> | null | undefined,
  hookOptions?: UseHookOptions,
): UseResourceResult<RowHandle<Schema, TCollection>> & {
  row: RowHandle<Schema, TCollection> | undefined;
}
```

- `row: null | undefined` keeps the hook idle.
- `row` can be either a `RowHandle` or a `RowRef<"boards">`-style ref. `RowRef` only takes the collection name generic.
- `useRow` polls for changes and re-renders automatically. In React, prefer it over manual polling around `db.getRow(...)`.
- The returned handle matches `db.getRow(...)`, including parent collection constraints.
- Use `row` as the primary payload field and `isLoading` for the common loading check.

### `useShareLink`

```ts
function useShareLink<Schema extends DbSchema>(
  db: Vennbase<Schema>,
  row: RowInput | null | undefined,
  role: "editor" | "contributor" | "viewer" | "submitter",
  options?: UseHookOptions,
): {
  shareLink: string | undefined;
  ...
}
```

- `row: null | undefined` keeps the hook idle.
- `row` can be either a `RowHandle` or `RowRef`.
- `shareLink` is the generated or reused invite URL for the row.

### `useAcceptInviteFromUrl`

```ts
interface OpenedInviteResult<Schema extends DbSchema> {
  kind: "opened";
  ref: RowRef;
  role: "editor" | "contributor" | "viewer";
  row: AnyRowHandle<Schema>;
}

interface JoinedInviteResult {
  kind: "joined";
  ref: RowRef;
  role: "submitter";
}

type AcceptedInviteResult<Schema extends DbSchema> =
  | OpenedInviteResult<Schema>
  | JoinedInviteResult;

interface UseAcceptInviteFromUrlOptions<Schema extends DbSchema> extends UseHookOptions {
  url?: string | null;
  clearInviteParams?: boolean | ((url: URL) => string);
  onOpen?: (row: AnyRowHandle<Schema>) => void | Promise<void>;
  onResolve?: (result: AcceptedInviteResult<Schema>) => void | Promise<void>;
}

interface UseAcceptInviteFromUrlResult<Schema extends DbSchema>
  extends UseResourceResult<AcceptedInviteResult<Schema>> {
  hasInvite: boolean;
  inviteInput: string | null;
}

function useAcceptInviteFromUrl<Schema extends DbSchema>(
  db: Vennbase<Schema>,
  options?: UseAcceptInviteFromUrlOptions<Schema>,
): UseAcceptInviteFromUrlResult<Schema>
```

- `url` defaults to `window.location.href`.
- `enabled` defaults to `true`
- `clearInviteParams` defaults to `true`.
- `onOpen` runs only for readable invites and receives the opened row directly.
- `onResolve` runs after invite resolution succeeds and may be async.
- Readable invites resolve to `{ kind: "opened", row, ref, role }`.
- Submitter invites resolve to `{ kind: "joined", ref, role: "submitter" }`.
- The hook stays in `loading` until `onOpen` and `onResolve` finish and the invite params are removed from the current URL.

### `useMutation`

```ts
function useMutation<TArgs extends unknown[], TResult>(
  fn: (...args: TArgs) => Promise<TResult>,
): {
  mutate: (...args: TArgs) => Promise<TResult>;
  data: TResult | undefined;
  status: "idle" | "loading" | "success" | "error";
  error: unknown;
  reset(): void;
}
```
- Use it to wrap writes like `db.create(...)`, `db.update(...)`, or any other async workflow you want to expose as a React action state.
[rerun: b3]

Agent

Now let me read PATTERNS.md and look at the appointment-app example:

Agent

Input

$ cd "/Users/alex/code/experiment vennbase 1" && cat node_modules/@vennbase/core/PATTERNS.md 2>/dev/null | head -300

Output

# Advanced patterns — appointment-app

The `packages/appointment-app` example demonstrates three access-control patterns for booking and claiming shared resources. This is a recipe-style walkthrough of each.

Run the app with:

```bash
pnpm --filter appointment-app dev
```

The schema lives in `packages/appointment-app/src/schema.ts`. The service layer lives in `packages/appointment-app/src/service.ts`.

---

## Pattern 1: Blind booking inbox

**Problem.** Customers need to create bookings under a parent row that only the owner can read. The owner doesn't want to send each customer a separate invite.

**Trick.** Store the submitter link for the hidden `bookingRoots` row as a plain string field on the *readable* `schedules` row. Any viewer of the schedule calls `joinInvite(...)` on that embedded link to gain submitter access to the inbox — without ever getting readable access to it.

**Owner side — create the inbox and embed its link in the schedule:**

```ts
const bookingRootWrite = this.db.create("bookingRoots", { createdAt: Date.now() });
const bookingRoot = bookingRootWrite.value;
const bookingSubmitterLinkWrite = this.db.createShareLink(bookingRoot, "submitter");
const scheduleWrite = this.db.create("schedules", {
  ...draftToScheduleFields(draft),
  bookingSubmitterLink: bookingSubmitterLinkWrite.value,  // stored as a plain string field on the readable row
});

await Promise.all([
  scheduleWrite.committed,
  bookingRootWrite.committed,
  bookingSubmitterLinkWrite.committed,
]);
```

**Customer side — claim submitter access from the embedded link:**

```ts
async ensureBookingRootAccess(schedule: ScheduleHandle): Promise<BookingRootRef> {
  const joined = await this.db.joinInvite(schedule.fields.bookingSubmitterLink);
  return joined.ref as BookingRootRef;
}
```

`joinInvite` is idempotent — calling it again on a link the user already joined is a no-op. Call it every time a customer opens a schedule; no local state needed.

The customer never holds a viewer link to `bookingRoots` itself, so they cannot read the parent row, inspect its members, or see other customers' full booking records.

That has an important consequence: a blind inbox lets a submitter **create** child rows, but not later rediscover them as full rows from the inbox itself. If the app needs self-cancel, self-edit, or "show me my booking" flows, write a second private record the submitter owns at creation time:

```ts
const bookingWrite = await this.db.create("bookings", {
  slotStartMs: args.slotStartMs,
  slotEndMs: args.slotEndMs,
  claimedAtMs: Date.now(),
}, {
  in: args.bookingRootRef,
}).committed;

await this.db.create("savedBookings", {
  scheduleRef: toRowRef(args.schedule),
  bookingRef: toRowRef(bookingWrite),
  status: "active",
  slotStartMs: args.slotStartMs,
  slotEndMs: args.slotEndMs,
}, {
  in: CURRENT_USER,
}).committed;
```

Later, the app reopens the shared booking through that private `bookingRef` and cancels it by removing the parent link. The blind inbox stays blind; the submitter's private record is what makes revisit flows possible.

---

## Pattern 2: Index-key sibling visibility with `select: "indexKeys"`

**Problem.** Customers need to see which slots currently look occupied so they can avoid obvious collisions — but they shouldn't see other customers' private booking details.

**Trick.** Query with `select: "indexKeys"`. Submitters can run this query against the inbox without needing read access to the parent. The response is an index-key projection: it includes only `kind`, `id`, `collection`, and index-key-only `fields`.

**In the UI** — reactive:

```ts
const { rows: sharedBookings = [] } = useQuery(db, "bookings", {
  in: props.bookingRootRef,
  select: "indexKeys",
  limit: 500,
});
```

In the appointment example, the flow is **write first, then converge on the read path**:

```ts
await this.db.create("bookings", {
  slotStartMs: args.slotStartMs,
  slotEndMs: args.slotEndMs,
  claimedAtMs: Date.now(),
}, {
  in: args.bookingRootRef,
}).committed;
```

Then derive the visible winning claim from the visible rows:

1. group claims by `{ slotStartMs, slotEndMs }`
2. sort each group by `(claimedAtMs, id)`
3. use a fixed app-level cooloff window such as 5 seconds
4. before `firstClaim.claimedAtMs + cooloffMs`, treat the slot as `pending`
5. after cooloff, treat only the first claim as active
6. if that claim disappears later, recompute from the remaining rows and the next claim becomes active

`select: "indexKeys"` works in both `useQuery` and the imperative `db.query`. No additional permissions are required — submitter access already allows index-key sibling queries. These projections are not locatable row refs; use a full query if you need to reopen a row later.

Important: this pattern gives **shared visibility and client convergence only**.

- It does not enforce uniqueness or capacity.
- It does not prevent oversubscription.
- It is not fair against malicious writers.
- It should not be described as a hard reservation mechanism.

This gives **honest convergence**, not enforcement. All well-behaved clients will compute the same visible winner from the same visible rows, but a malicious writer can still bias the outcome by choosing favorable visible tiebreak values.

---

## Pattern 3: Minimal index-key fields

`select: "indexKeys"` only exposes fields declared `.indexKey()`. The `bookings` schema is designed so index-key projections contain just enough to render an occupied-slots calendar — nothing more:

```ts
bookings: collection({
  in: ["bookingRoots"],
  fields: {
    slotStartMs: field.number().indexKey(),  // exposed by select: "indexKeys"
    slotEndMs:   field.number().indexKey(),  // exposed by select: "indexKeys"
    claimedAtMs: field.number().indexKey(),  // visible tiebreak for read-side arbitration
  },
}),
```

**Design rule:** before marking a field `.indexKey()`, ask whether it is safe for submitters to read. If not, leave `.indexKey()` off and it will never appear in index-key projections, regardless of what is added to the schema later. For this pattern, `claimedAtMs` is intentionally visible so all clients can run the same deterministic tiebreak.

---

## How the three patterns compose

The app wires all three together into a single access-control surface the owner never has to touch again:

1. **Owner creates a schedule.** During creation, a hidden `bookingRoots` row is created and its submitter link is stored in `schedule.fields.bookingSubmitterLink`.
2. **Owner shares the schedule** using a viewer share link. Customers open it.
3. **Customer joins the inbox** — Pattern 1. `ensureBookingRootAccess` calls `joinInvite` on the embedded link, returning a `BookingRootRef` with submitter access.
4. **Customer creates a claim** under the `BookingRootRef` and immediately stores its `bookingRef` in a private user-scoped row. No preflight race check is needed.
5. **Customer queries visible claims** — Patterns 2 and 3. `select: "indexKeys"` returns index-key projections with `fields: { slotStartMs, slotEndMs, claimedAtMs }` from sibling bookings. Clients apply a fixed cooloff window and the `(claimedAtMs, id)` tiebreak to decide which visible claim currently wins.
6. **Owner and customers converge** on the same visible winning claim from the same visible rows. Only the owner (with full access) can read the complete booking records.

The owner never manually grants or revokes customer access. The submitter link embedded in the schedule is the entire access-control surface.
[rerun: b4]

Agent

Now let me check the current project structure:

Agent

Input

{"description":"Plan fitness studio booking app","subagent_type":"Plan","prompt":"Plan a complete fitness studio booking web app. This is a client-side only app with no backend.\n\n## Stack\n- React (...

Output

Now I have everything I need to design a complete implementation plan. Let me compile this into a thorough plan.

---

# Fitness Studio Booking App — Complete Implementation Plan

## Overview

The project directory already has `@vennbase/core`, `@vennbase/react`, React 19, and `puter` installed. React, Vite, TypeScript, and `react-dom` need to be added. The complete file tree to build from scratch is roughly 15 files.

---

## Build Setup Files (create first)

### 1. `package.json` (update)

Add the missing dependencies and scripts. The current `package.json` has no `devDependencies` and no scripts. It needs:

```json
{
  "name": "fitness-studio-booking",
  "private": true,
  "type": "module",
  "scripts": {
    "dev": "vite",
    "build": "tsc -b && vite build",
    "preview": "vite preview"
  },
  "dependencies": {
    "@vennbase/core": "^0.1.16",
    "@vennbase/react": "^0.1.16",
    "puter": "^1.0.0",
    "react": "^19.0.0",
    "react-dom": "^19.0.0"
  },
  "devDependencies": {
    "@types/react": "^19.0.0",
    "@types/react-dom": "^19.0.0",
    "@vitejs/plugin-react": "^4.0.0",
    "typescript": "^5.0.0",
    "vite": "^5.0.0"
  }
}
```

Note: the `puter` npm package is a node CLI tool (the `node_modules` tree shows `open`, `default-browser` etc as its deps). The actual Puter browser SDK (`puter.js`) is loaded via a `<script>` tag in `index.html` — Vennbase uses `@heyputer/puter.js` under the hood already bundled into its own dist.

### 2. `vite.config.ts`

```ts
import { defineConfig } from "vite";
import react from "@vitejs/plugin-react";

export default defineConfig({
  plugins: [react()],
});
```

No special config needed. Vennbase's `@heyputer/puter.js` dependency uses native ES modules and should tree-shake fine.

### 3. `tsconfig.json`

Standard Vite/React tsconfig:

```json
{
  "compilerOptions": {
    "target": "ES2020",
    "useDefineForClassFields": true,
    "lib": ["ES2020", "DOM", "DOM.Iterable"],
    "module": "ESNext",
    "skipLibCheck": true,
    "moduleResolution": "bundler",
    "allowImportingTsExtensions": true,
    "isolatedModules": true,
    "moduleDetection": "force",
    "noEmit": true,
    "jsx": "react-jsx",
    "strict": true
  },
  "include": ["src"]
}
```

`moduleResolution: "bundler"` is important — `@vennbase/core` uses `.js` extension imports in its source, and the bundler resolver handles that correctly when Vite processes the package.

### 4. `index.html`

```html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Studio Booking</title>
  </head>
  <body>
    <div id="root"></div>
    <script type="module" src="/src/main.tsx"></script>
  </body>
</html>
```

No `puter.js` CDN script tag is needed — Vennbase bundles `@heyputer/puter.js` as an npm dep which handles the Puter auth bridge. Confirm by checking `node_modules/@heyputer` — it's already present.

### 5. `src/main.tsx`

```tsx
import { StrictMode } from "react";
import { createRoot } from "react-dom/client";
import { VennbaseProvider } from "@vennbase/react";
import { db } from "./db";
import { App } from "./App";

createRoot(document.getElementById("root")!).render(
  <StrictMode>
    <VennbaseProvider db={db}>
      <App />
    </VennbaseProvider>
  </StrictMode>
);
```

---

## Core App Files

### 6. `src/schema.ts`

Directly from the spec. A few decisions worth noting:

- `bookingRoots` has no `in` — it is top-level, accessed only through share links.
- `studios` also has no `in` — top-level.
- `bookingSubmitterLink` is on `studios`, not on `bookingRoots`, so customers reading the studio viewer link can extract it.
- `classId` on `bookings` is a plain `field.string()` not a `field.ref("classes")` — this is intentional. Submitters cannot access the `studios` or `classes` collections, so a typed ref would fail when trying to resolve it. Storing `classId` as a string allows the owner to resolve it via their own full class list.
- All fields that submitters need to read (for slot counting convergence logic) are `.indexKey()`.

```ts
import { collection, defineSchema, field } from "@vennbase/core";

export const schema = defineSchema({
  studios: collection({
    fields: {
      name: field.string(),
      bookingSubmitterLink: field.string(),
      createdAt: field.number().indexKey(),
    },
  }),

  classes: collection({
    in: ["studios"],
    fields: {
      name: field.string(),
      startMs: field.number().indexKey(),
      endMs: field.number().indexKey(),
      limit: field.number().indexKey(),
      createdAt: field.number().indexKey(),
    },
  }),

  bookingRoots: collection({
    fields: {
      createdAt: field.number(),
    },
  }),

  bookings: collection({
    in: ["bookingRoots"],
    fields: {
      classId: field.string().indexKey(),
      bookedAtMs: field.number().indexKey(),
    },
  }),

  myStudios: collection({
    in: ["user"],
    fields: {
      studioRef: field.ref("studios").indexKey(),
      openedAt: field.number().indexKey(),
    },
  }),

  myBookings: collection({
    in: ["user"],
    fields: {
      studioRef: field.ref("studios").indexKey(),
      classId: field.string().indexKey(),
      bookingRef: field.ref("bookings").indexKey(),
      status: field.string().indexKey(),
      bookedAtMs: field.number().indexKey(),
    },
  }),
});

export type Schema = typeof schema;
```

### 7. `src/db.ts`

```ts
import { Vennbase } from "@vennbase/core";
import { schema } from "./schema";

export const db = new Vennbase({
  schema,
  appBaseUrl: window.location.origin,
});
```

The `appBaseUrl` ensures `db.createShareLink(...)` generates links that point back to this app. This is critical for invite URLs to work when customers open the shared link.

---

## App Shell

### 8. `src/App.tsx`

This is the root component. It handles three concerns:
1. Session gating (sign-in wall)
2. URL invite handling (customer landing flow)
3. Role determination → routing to `OwnerView` or `CustomerView`

Key design decisions:

**Role detection**: After loading a studio, call `db.whoAmI()` and compare to `studio.owner`. If they match → owner view. Otherwise → customer view. This is more reliable than checking the invite result role because:
- An owner who navigates back (no URL params) would have no invite result but still needs owner view.
- The `useSavedRow` restore path also bypasses invite processing entirely.

**Invite URL flow**: `useAcceptInviteFromUrl` handles `?db=...` URL params. It calls `db.acceptInvite(...)` which opens the studio as a viewer. The `onResolve` callback saves the studio via `useSavedRow`. After that, the customer still needs to call `db.joinInvite(studio.fields.bookingSubmitterLink)` to get submitter access to `bookingRoots` — this happens in `CustomerView` or a hook.

**Saved row restore**: `useSavedRow(db, { key: "studio", collection: "studios" })` restores the studio on subsequent visits. The `loadSavedRow` option can be used to eagerly fetch the studio on restore.

Structure:

```tsx
export function App() {
  const session = useSession(db);

  // Not yet signed in
  if (session.status === "loading") return <LoadingSpinner />;
  if (!session.session?.signedIn) return <SignInPage onSignIn={() => void session.signIn()} />;

  return <StudioLoader />;
}

function StudioLoader() {
  // Try restoring from saved row first
  const saved = useSavedRow(db, { key: "studio", collection: "studios" });

  // Handle incoming invite URL
  const invite = useAcceptInviteFromUrl(db, {
    clearInviteParams: true,
    onResolve: async (result) => {
      if (result.kind === "opened") {
        await saved.save(result.row);
      }
      // "joined" kind means submitter-only; shouldn't happen for the studio invite
    },
  });

  const studio = saved.row ?? (invite.data?.kind === "opened" ? invite.data.row : undefined);

  if (saved.isLoading || invite.isLoading) return <LoadingSpinner />;
  if (!studio) return <WelcomePage />;  // No studio yet — owner creates one here

  return <StudioApp studio={studio} />;
}

function StudioApp({ studio }) {
  const currentUser = useCurrentUser(db);
  const isOwner = currentUser.user?.username === studio.owner;

  if (isOwner) return <OwnerView studio={studio} />;
  return <CustomerView studio={studio} />;
}
```

**Gotcha**: `useAcceptInviteFromUrl` will fire even on owner's repeat visits if a `?db=` param somehow remains in the URL. Use `clearInviteParams: true` to strip the param after processing. The `onResolve` callback's `result.kind` guards against unexpected submitter invites.

**Gotcha**: The `useSavedRow` row is loaded from Puter-backed storage and may be stale. The `loadSavedRow` option lets you call `row.refresh()` to re-fetch fields before returning the row. Use this to ensure `bookingSubmitterLink` is fresh.

---

## Hooks

### 9. `src/hooks/useStudio.ts`

Encapsulates the "get or create studio" logic for the owner. Thin wrapper:

```ts
export function useCreateStudio() {
  // Returns a mutate fn that:
  // 1. Creates bookingRoots row
  // 2. Awaits bookingRoots.committed (needed before createShareLink can be used by others)
  // 3. Creates submitter share link for bookingRoots
  // 4. Creates studio row with bookingSubmitterLink field
  // 5. Awaits all .committed
  // 6. Returns studio RowHandle
}
```

The **critical sequencing** here (from PATTERNS.md):

```ts
const bookingRootReceipt = db.create("bookingRoots", { createdAt: Date.now() });
const bookingRoot = bookingRootReceipt.value;  // optimistic handle
const submitterLinkReceipt = db.createShareLink(bookingRoot, "submitter");

const studioReceipt = db.create("studios", {
  name,
  bookingSubmitterLink: submitterLinkReceipt.value,  // optimistic link value
  createdAt: Date.now(),
});

// Await all three to be remotely confirmed before the owner can share the studio link
await Promise.all([
  bookingRootReceipt.committed,
  submitterLinkReceipt.committed,
  studioReceipt.committed,
]);
```

The `.value` of `submitterLinkReceipt` is the optimistic URL, which is already a valid URL because `createShareLink` mints it locally. However, `.committed` must resolve before a remote client can actually use that token — so the owner should not copy the share link until all three writes are confirmed.

### 10. `src/hooks/useBookings.ts`

Two usage modes:

**Owner mode** — full rows, needed to show owner identity and any booking management:

```ts
export function useOwnerBookings(bookingRootRef: RowRef | undefined) {
  return useQuery(db, "bookings", bookingRootRef ? {
    in: bookingRootRef,
    orderBy: "bookedAtMs",
    order: "asc",
  } : null);
}
```

**Customer mode** — index-key projections only:

```ts
export function useIndexKeyBookings(bookingRootRef: RowRef | undefined) {
  return useQuery(db, "bookings", bookingRootRef ? {
    in: bookingRootRef,
    select: "indexKeys",
    orderBy: "bookedAtMs",
    order: "asc",
  } : null);
}
```

**Convergence logic** — pure function, applied in rendering:

```ts
const COOLOFF_MS = 5000;

export function getActiveBookingsForClass(
  projections: DbIndexKeyProjection<Schema, "bookings">[],
  classId: string,
  nowMs: number
): { activeCount: number; isPending: boolean } {
  const forClass = projections
    .filter(p => p.fields.classId === classId)
    .sort((a, b) => {
      const timeDiff = a.fields.bookedAtMs - b.fields.bookedAtMs;
      if (timeDiff !== 0) return timeDiff;
      return a.id < b.id ? -1 : 1;  // stable tiebreak
    });

  if (forClass.length === 0) return { activeCount: 0, isPending: false };

  const firstBookedAt = forClass[0].fields.bookedAtMs;
  const cooloffExpired = nowMs > firstBookedAt + COOLOFF_MS;

  if (!cooloffExpired) {
    return { activeCount: forClass.length, isPending: true };
  }

  // After cooloff: only the first (lowest bookedAtMs, then id) booking per slot counts
  // For a fitness app this simplifies to: all visible bookings are active (each user books once per class)
  // If we wanted strict capacity: activeCount = Math.min(forClass.length, classLimit)
  return { activeCount: forClass.length, isPending: false };
}
```

**Note on the convergence model for fitness apps**: Unlike a single appointment slot (one winner), a fitness class has `limit` slots. The convergence question is "are we over capacity?" Each customer books one row; there's no winner/loser within capacity. The cooloff window matters primarily when many people book simultaneously near the limit. After cooloff, count all visible bookings; if count >= limit, show "Full". If count > limit, the over-capacity users see a "may be full" warning but aren't hard-rejected — this matches the stated "honest convergence" model.

---

## View Components

### 11. `src/components/OwnerView.tsx`

Responsibilities:
- Show studio name + copy shareable viewer link button
- Show class list with booking counts
- Add-class form

**Shareable link**: Use `useShareLink(db, studio, "viewer")` which returns `{ shareLink }`. Display a copy button.

**Class list**: `useQuery(db, "classes", { in: studio, orderBy: "startMs", order: "asc" })` — returns full `RowHandle` array since the owner has editor access.

**Booking counts per class**: The owner can query full bookings against `bookingRootRef`. They need the `bookingRootRef` — but it's only stored as a string `bookingSubmitterLink`. The owner *created* the `bookingRoots` row, so they already have editor access. They can call `db.joinInvite(studio.fields.bookingSubmitterLink)` to get the ref back (idempotent, returns `{ ref, role }`). Store this ref in state.

```tsx
const [bookingRootRef, setBookingRootRef] = useState<RowRef | undefined>();

useEffect(() => {
  if (!studio) return;
  db.joinInvite(studio.fields.bookingSubmitterLink).then(result => {
    setBookingRootRef(result.ref as RowRef<"bookingRoots">);
  });
}, [studio.id]);
```

Then use `useQuery(db, "bookings", { in: bookingRootRef, orderBy: "bookedAtMs" })` for full rows.

**Add-class form**: Controlled form with `name` (text), `startMs` (datetime-local → `new Date(value).getTime()`), `endMs` (datetime-local), `limit` (number). On submit: `db.create("classes", { name, startMs, endMs, limit, createdAt: Date.now() }, { in: studio })`. Optimistic so no async loading state needed.

**Gotcha**: The owner calls `joinInvite` on the submitter link to get the `bookingRootRef` back. `joinInvite` returns `{ ref, role }` — since the owner is already an editor of `bookingRoots` (they created it), the role may come back as `"editor"` not `"submitter"`. Either way, the ref is usable for a full query.

### 12. `src/components/CustomerView.tsx`

Responsibilities:
- Join the booking inbox (idempotent)
- Show class list with available slots
- Handle "Book" action
- Show customer's own bookings with cancel option

**Join inbox on mount**:

```tsx
const [bookingRootRef, setBookingRootRef] = useState<RowRef | undefined>();

useEffect(() => {
  db.joinInvite(studio.fields.bookingSubmitterLink).then(result => {
    setBookingRootRef(result.ref as RowRef<"bookingRoots">);
  });
}, [studio.id]);
```

**Classes**: `useQuery(db, "classes", { in: studio, orderBy: "startMs", order: "asc" })` — the customer has viewer access to the studio and its children, so this works.

**Index-key bookings**: `useQuery(db, "bookings", { in: bookingRootRef, select: "indexKeys" })` — requires submitter access which `joinInvite` provides.

**Own bookings**: `useQuery(db, "myBookings", { in: CURRENT_USER, where: { studioRef: studio.ref }, orderBy: "bookedAtMs", order: "desc" })`.

**Booking action**:

```ts
async function bookClass(classHandle: RowHandle<Schema, "classes">) {
  // Optimistic — use .value immediately
  const bookingReceipt = db.create("bookings", {
    classId: classHandle.id,
    bookedAtMs: Date.now(),
  }, { in: bookingRootRef! });

  // Also save private record immediately (optimistic)
  db.create("myBookings", {
    studioRef: studio.ref,
    classId: classHandle.id,
    bookingRef: bookingReceipt.value.ref,
    status: "active",
    bookedAtMs: Date.now(),
  }, { in: CURRENT_USER });

  // Await both remotely for correctness
  await bookingReceipt.committed;
}
```

**Cancellation**:

```ts
async function cancelBooking(myBooking: RowHandle<Schema, "myBookings">) {
  // Remove booking from the inbox (customer owns the booking row they created)
  db.removeParent(myBooking.fields.bookingRef, bookingRootRef!);

  // Mark private record as cancelled (optimistic)
  db.update("myBookings", myBooking, { status: "cancelled" });
}
```

**Gotcha**: `db.removeParent(child, parent)` takes `RowInput` for both. The customer has `myBooking.fields.bookingRef` as a `RowRef<"bookings">` — this is a valid `RowInput`. They also have `bookingRootRef` from `joinInvite`. Both are available. This works because the customer *owns* the booking row they created.

**Gotcha**: `myBooking.fields.bookingRef` is typed as `RowRef<"bookings">` (from the schema `field.ref("bookings")`). Pass it directly to `db.removeParent(...)`. Do not call `db.getRow(bookingRef)` first — `removeParent` accepts `RowInput` which includes raw refs.

### 13. `src/components/ClassList.tsx`

A shared presentational component that renders a list of classes. It accepts the class rows and a render-prop or slot for the action area (book button or booking count), so it can be reused between owner and customer views.

```tsx
interface ClassListProps {
  classes: RowHandle<Schema, "classes">[];
  renderAction: (cls: RowHandle<Schema, "classes">) => React.ReactNode;
}
```

### 14. `src/components/BookingRow.tsx`

Renders a single class row for the customer:
- Class name, time range (formatted from `startMs`/`endMs`)
- Slot availability: calls `getActiveBookingsForClass(projections, cls.id, Date.now())` to get active count, then shows `limit - activeCount` slots or "Full"
- "Book" button (disabled if full or already booked)
- Shows pending state during cooloff window

For "already booked" detection: check `myBookings` rows where `classId === cls.id && status === "active"`.

Props:
```tsx
interface BookingRowProps {
  cls: RowHandle<Schema, "classes">;
  projections: DbIndexKeyProjection<Schema, "bookings">[];
  myBookings: RowHandle<Schema, "myBookings">[];
  onBook: (cls: RowHandle<Schema, "classes">) => void;
  onCancel: (myBooking: RowHandle<Schema, "myBookings">) => void;
}
```

---

## Complete File Creation Order

1. `package.json` — updated with all deps and scripts
2. `tsconfig.json` — TypeScript config
3. `vite.config.ts` — Vite + React plugin
4. `index.html` — entry HTML
5. `src/schema.ts` — schema definition
6. `src/db.ts` — Vennbase instance
7. `src/main.tsx` — React root + VennbaseProvider
8. `src/App.tsx` — session gate, invite handler, role routing
9. `src/hooks/useStudio.ts` — create studio hook
10. `src/hooks/useBookings.ts` — booking queries + convergence logic
11. `src/components/ClassList.tsx` — shared class list presentation
12. `src/components/BookingRow.tsx` — per-class row with slot display
13. `src/components/OwnerView.tsx` — owner management view
14. `src/components/CustomerView.tsx` — customer booking view

---

## Security-Critical Implementation Notes

**1. Who can read `bookingRoots`?**
Nobody except the owner. The `bookingRoots` row is created by the owner and never shared as a viewer link. Only the submitter link is stored. Customers calling `joinInvite(submitterLink)` get submitter role — they can create children and query with `select: "indexKeys"`, nothing more.

**2. What do submitters see in index-key projections?**
Only `classId`, `bookedAtMs`, and the row `id`. No owner identity, no booking timestamps beyond `bookedAtMs`, no other customer PII. This is enforced by Vennbase's server-side access model, not client code.

**3. Can a customer read another customer's booking details?**
No. Index-key projections strip `owner`, `ref`, `baseUrl`, and all non-indexKey fields. Even if a customer modifies their client code to call `db.getRow(someBookingRef)`, they would not have the ref (projections don't expose it) and the server would reject any direct fetch they attempted without a valid ref+token pair.

**4. Can the owner be impersonated?**
No. `studio.owner` is set server-side by Vennbase when the row is created. The client reads it from the returned `RowHandle` but cannot spoof it. The `db.whoAmI()` call returns the authenticated Puter user identity.

**5. `joinInvite` idempotency**
Both owner and customer call `joinInvite(studio.fields.bookingSubmitterLink)` to retrieve the `bookingRootRef`. This is safe — the API docs confirm idempotency. The owner will get back their editor role; the customer gets submitter.

**6. Booking cancellation race**
`db.removeParent` is optimistic. If the booking was already cancelled (e.g., duplicate cancel click), the server will reject the redundant remove but the local optimistic state will show it cancelled. Update `myBookings.status` to "cancelled" optimistically in the same synchronous tick to prevent double-cancel clicks.

---

## Open Questions / Gotchas

1. **`field.ref("studios")` in `myStudios.studioRef`**: The `field.ref(collections)` signature takes a collection name string (or array). The generated type will be `RowRef<"studios">`. When querying `myStudios` with `where: { studioRef: studio.ref }`, the `studio.ref` must be a `RowRef<"studios">` which it is. This should work.

2. **`myStudios` collection usage**: The spec defines it but the primary "saved studio" mechanism is `db.saveRow("studio", studio)` / `db.openSavedRow("studio", "studios")` via `useSavedRow`. The `myStudios` collection would be used if users need to track *multiple* studios (e.g., a customer that has visited multiple studios). For V1 with single-studio flows, `useSavedRow` with a fixed key is simpler. Decide which to use — `myStudios` + `useQuery` allows multi-studio history; `useSavedRow` is simpler but single-slot.

3. **`WelcomePage` for the owner**: When no saved studio exists and no invite URL is present, the app shows a welcome page. This is where the owner creates their first studio. The create flow should be clearly gated: only signed-in users reach this page. The welcome page shows an "I'm a studio owner — create studio" form and a "I'm a customer — paste a studio link" input.

4. **`datetime-local` input parsing**: HTML `datetime-local` returns a string like `"2026-04-10T09:30"`. Parse with `new Date(value).getTime()`. Note that `new Date("2026-04-10T09:30")` is parsed as local time in modern browsers — this is correct for a studio schedule app.

5. **Cooloff window display**: During the 5-second cooloff, show "Booking..." state (slightly ambiguous slot count). After cooloff, show the definitive count. Use `Date.now()` refreshed via a `useInterval` or rely on `useQuery`'s re-render cadence.

6. **No `myStudios.studioRef` where clause**: The `useQuery` `where` clause requires index-key fields. `studioRef` is `field.ref("studios").indexKey()` — so this works. The where filter `{ studioRef: studio.ref }` will match on the RowRef value.

7. **Installing remaining deps**: Run `npm install react react-dom @vitejs/plugin-react vite typescript @types/react @types/react-dom` before running `npm run dev`.

---

### Critical Files for Implementation

- `/Users/alex/code/experiment vennbase 1/src/App.tsx`
- `/Users/alex/code/experiment vennbase 1/src/schema.ts`
- `/Users/alex/code/experiment vennbase 1/src/components/CustomerView.tsx`
- `/Users/alex/code/experiment vennbase 1/src/components/OwnerView.tsx`
- `/Users/alex/code/experiment vennbase 1/src/hooks/useBookings.ts`

Agent

Input

$ cat "/Users/alex/code/experiment vennbase 1/node_modules/@vennbase/core/dist/types.d.ts" 2>/dev/null

Output

import type { KV, Puter } from "@heyputer/puter.js";
import type { MemberRole, RowRef } from "./schema.js";
export interface BackendKv extends Pick<KV, "get" | "set" | "del" | "list"> {
}
export type BackendClient = Pick<Puter, "auth" | "getUser" | "fs" | "workers"> & {
    kv?: BackendKv;
};
export type JsonValue = string | number | boolean | null | RowRef | {
    [key: string]: JsonValue;
} | JsonValue[];
export type ErrorCode = "SIGNED_OUT" | "UNAUTHORIZED" | "INVALID_SIGNATURE" | "INVITE_REQUIRED" | "KEY_MISMATCH" | "BAD_REQUEST";
export interface ApiError {
    code: ErrorCode;
    message: string;
}
export interface VennbaseUser {
    username: string;
}
export type AuthSession = {
    signedIn: false;
} | {
    signedIn: true;
    user: VennbaseUser;
};
export interface Row {
    id: string;
    name: string;
    owner: string;
    baseUrl: string;
    createdAt: number;
}
export interface SyncMessage {
    id: string;
    rowId: string;
    body: JsonValue;
    createdAt: number;
    signedBy: string;
    sequence: number;
}
export interface ShareToken {
    token: string;
    rowId: string;
    invitedBy: string;
    createdAt: number;
    role: MemberRole;
}
export interface JoinOptions {
    inviteToken?: string;
}
export interface PrincipalProof {
    username: string;
    publicKeyJwk: JsonWebKey;
    signedAt: number;
    expiresAt: number;
    signature: string;
}
export interface RequestProof {
    action: string;
    rowId: string;
    nonce: string;
    signedAt: number;
    signature: string;
}
export interface ProtectedRequest<TPayload> {
    auth: {
        principal: PrincipalProof;
        request?: RequestProof;
    };
    payload: TPayload;
}
export interface VerifiedPrincipal {
    username: string;
    publicKeyJwk: JsonWebKey;
    publicKey: CryptoKey;
    signedAt: number;
    expiresAt: number;
    signature: string;
    proof: PrincipalProof;
}
export interface CrdtConnectCallbacks {
    applyRemoteUpdate: (body: JsonValue, message: SyncMessage) => void;
    produceLocalUpdate: () => JsonValue | null;
}
export interface CrdtAdapter<TValue> {
    callbacks: CrdtConnectCallbacks;
    getValue(): TValue;
    getVersion(): number;
    subscribe(listener: () => void): () => void;
    reset(): void;
}
export interface CrdtConnection {
    disconnect(): void;
    flush(): Promise<void>;
}
export interface ParsedInvite {
    ref: RowRef;
    shareToken?: string;
}
export interface DeployWorkerArgs {
    owner: string;
    rowId: string;
    rowName: string;
    script: string;
    ownerPublicKeyJwk?: JsonWebKey;
    workerName?: string;
    workerVersion?: number;
    appHostname?: string;
    appHostHash?: string;
}
export interface RowSnapshot extends Row {
    collection: string | null;
    members: string[];
    parentRefs: RowRef[];
}
[rerun: b13]

Agent

Input

$ cat "/Users/alex/code/experiment vennbase 1/node_modules/@vennbase/core/dist/schema.d.ts" 2>/dev/null | grep -A5 "isIndexKeyProjection\|DbIndexKeyProjection\|RowRef\|RowInput\|QueryWhere\|DbCreateOptions"

Output

export interface RowRef<TCollection extends string = string> {
    id: string;
    collection: TCollection;
    baseUrl: string;
}
export type RowTarget<TCollection extends string = string> = RowRef<TCollection> | {
    ref: RowRef<TCollection>;
};
export type RowInput<TCollection extends string = string> = RowTarget<TCollection>;
export type DbFieldValue = string | number | boolean | RowRef;
export type FieldType = "string" | "number" | "boolean" | "date" | "ref";
export type DbRowFields = {
    [key: string]: DbFieldValue | undefined;
};
export declare const BUILTIN_USER_SCOPE: "user";
--
export declare function isRowRef<TCollection extends string = string>(value: unknown): value is RowRef<TCollection>;
export declare function toRowRef<TCollection extends string>(row: RowTarget<TCollection>): RowRef<TCollection>;
export interface DbFieldBuilder<TValue extends DbFieldValue = DbFieldValue, TType extends FieldType = FieldType, TOptional extends boolean = false, THasDefault extends boolean = false, TIsIndexKey extends boolean = false> {
    readonly kind: "field";
    readonly type: TType;
    readonly isOptional: TOptional;
    readonly hasDefault: THasDefault;
--
    readonly ref: <const TCollections extends string | readonly string[]>(collections: TCollections) => DbFieldBuilder<RowRef<TCollections extends string ? TCollections : TCollections extends readonly string[] ? TCollections[number] : never>, "ref", false, false, false>;
};
export type DbCollectionDefinition<TFields extends Record<string, AnyDbFieldBuilder> = Record<string, AnyDbFieldBuilder>, TParents extends readonly string[] | undefined = undefined> = {
    readonly fields: TFields;
} & (TParents extends readonly string[] ? {
    readonly in: TParents;
--
export type AnyRowRef<Schema extends DbSchema> = {
    [TCollection in CollectionName<Schema>]: RowRef<TCollection>;
}[CollectionName<Schema>];
type ParentInput<TCollection extends string> = [
    TCollection
] extends [never] ? never : Array<RowInput<TCollection> | (BuiltInUserScope extends TCollection ? CurrentUser : never)> | RowInput<TCollection> | (BuiltInUserScope extends TCollection ? CurrentUser : never);
export type AllowedParentRef<Schema extends DbSchema, TCollection extends CollectionName<Schema>> = RowRef<AllowedParentCollections<Schema, TCollection>>;
export interface DbRow<TCollection extends string = string, TFields extends DbRowFields = DbRowFields> extends RowRef<TCollection> {
    fields: TFields;
}
export type AnyRow<Schema extends DbSchema> = {
    [TCollection in CollectionName<Schema>]: DbRow<TCollection, RowFields<Schema, TCollection>>;
}[CollectionName<Schema>];
export type DbCreateOptions<Schema extends DbSchema = DbSchema, TCollection extends CollectionName<Schema> = CollectionName<Schema>> = HasDeclaredParents<Schema, TCollection> extends true ? {
    in: ParentInput<AllowedParentCollections<Schema, TCollection>>;
    name?: string;
} : {
    in?: never;
    name?: string;
--
export type DbCreateArgs<Schema extends DbSchema = DbSchema, TCollection extends CollectionName<Schema> = CollectionName<Schema>> = HasDeclaredParents<Schema, TCollection> extends true ? [options: DbCreateOptions<Schema, TCollection>] : [options?: DbCreateOptions<Schema, TCollection>];
type QueryFieldValue<TField extends AnyDbFieldBuilder> = Exclude<InferFieldValue<TField>, undefined>;
export type IndexKeyFieldNames<Schema extends DbSchema, TCollection extends CollectionName<Schema>> = {
    [K in keyof FieldDefinitions<Schema, TCollection>]-?: FieldIsIndexKey<FieldDefinitions<Schema, TCollection>[K]> extends true ? K : never;
}[keyof FieldDefinitions<Schema, TCollection>] & string;
export type QueryWhere<Schema extends DbSchema, TCollection extends CollectionName<Schema>> = Partial<{
    [K in IndexKeyFieldNames<Schema, TCollection>]: QueryFieldValue<FieldDefinitions<Schema, TCollection>[K]>;
}>;
type QueryBaseOptions<Schema extends DbSchema, TCollection extends CollectionName<Schema>> = HasDeclaredParents<Schema, TCollection> extends true ? {
    in: ParentInput<AllowedParentCollections<Schema, TCollection>>;
    where?: QueryWhere<Schema, TCollection>;
    orderBy?: IndexKeyFieldNames<Schema, TCollection>;
    order?: "asc" | "desc";
    limit?: number;
} : never;
export type DbQuerySelect = "full" | "indexKeys";
--
export interface DbIndexKeyProjection<Schema extends DbSchema = DbSchema, TCollection extends CollectionName<Schema> = CollectionName<Schema>> {
    kind: "index-key-projection";
    id: string;
    collection: TCollection;
    fields: IndexKeyRowFields<Schema, TCollection>;
}
export declare function isIndexKeyProjection<Schema extends DbSchema = DbSchema, TCollection extends CollectionName<Schema> = CollectionName<Schema>>(value: unknown): value is DbIndexKeyProjection<Schema, TCollection>;
export type DbQueryRow<Schema extends DbSchema = DbSchema, TCollection extends CollectionName<Schema> = CollectionName<Schema>, TSelect extends DbQuerySelect = "full"> = TSelect extends "indexKeys" ? DbIndexKeyProjection<Schema, TCollection> : RowHandle<Schema, TCollection>;
export type DbQueryRows<Schema extends DbSchema = DbSchema, TCollection extends CollectionName<Schema> = CollectionName<Schema>, TSelect extends DbQuerySelect = "full"> = Array<DbQueryRow<Schema, TCollection, TSelect>>;
export type InferDbQuerySelect<TOptions> = TOptions extends {
    select: "indexKeys";
} ? "indexKeys" : "full";
export type DbQueryOptions<Schema extends DbSchema = DbSchema, TCollection extends CollectionName<Schema> = CollectionName<Schema>, TSelect extends DbQuerySelect = "full"> = QueryBaseOptions<Schema, TCollection> & (TSelect extends "indexKeys" ? {
--
    via: "direct" | AnyRowRef<Schema>;
}
export declare function getCollectionSpec<Schema extends DbSchema, TCollection extends CollectionName<Schema>>(schema: Schema, collection: TCollection): Schema[TCollection];
export declare function collectionAllowsCurrentUser(collectionSpec: AnyDbCollectionDefinition): boolean;
export declare function resolveCollectionName<Schema extends DbSchema>(schema: Schema, collection: string | null | undefined): CollectionName<Schema>;
export declare function applyDefaults<TCollectionSpec extends AnyDbCollectionDefinition, TFields extends DbRowFields>(collectionSpec: TCollectionSpec, fields: TFields): TFields;
export declare function assertCreateParents(collection: string, collectionSpec: AnyDbCollectionDefinition, parents: RowRef[]): void;
export declare function getCollectionIndexKeyFieldNames(collectionSpec: AnyDbCollectionDefinition): string[];
export declare function pickIndexKeyFieldValues(collectionSpec: AnyDbCollectionDefinition, fields: Record<string, unknown>): Record<string, DbFieldValue>;
export declare function assertParentAllowed(schema: DbSchema, childCollection: string, parentCollection: string): void;
export declare function assertValidFieldValues(collection: string, collectionSpec: AnyDbCollectionDefinition, fields: Record<string, unknown>): void;
export {};
[rerun: b15]

Agent

Input

$ cat "/Users/alex/code/experiment vennbase 1/node_modules/@vennbase/react/dist/index.d.ts" 2>/dev/null | head -60

Output

import { type ReactNode } from "react";
import type { Vennbase } from "@vennbase/core";
import type { AuthSession, AnyRowHandle, CollectionName, CrdtAdapter, CrdtConnectCallbacks, CrdtConnection, DbMemberInfo, DbQueryOptions, DbQuerySelect, DbQueryRow, DbSchema, InferDbQuerySelect, MemberRole, VennbaseUser, RowRef, RowInput } from "@vennbase/core";
import type { RowHandle } from "@vennbase/core";
import type { ActivitySubscriber } from "./polling.js";
import { type LoadStatus, type ResourceSnapshot } from "./runtime.js";
export type { ActivitySubscriber } from "./polling.js";
export type { LoadStatus } from "./runtime.js";
export interface UseResourceResult<TData> extends ResourceSnapshot<TData> {
    isIdle: boolean;
    isLoading: boolean;
    isSuccess: boolean;
    isError: boolean;
    refresh(): Promise<void>;
}
export interface UseQueryResult<TRow> extends UseResourceResult<TRow[]> {
    rows: TRow[] | undefined;
}
export type UseShareLinkResult = Omit<UseResourceResult<string>, "data"> & {
    shareLink: string | undefined;
};
export interface UseSessionResult extends UseResourceResult<AuthSession> {
    session: AuthSession | undefined;
    signIn(): Promise<VennbaseUser>;
}
export interface UseCurrentUserResult extends UseResourceResult<VennbaseUser> {
    user: VennbaseUser | undefined;
}
export interface UseRowResult<Schema extends DbSchema, TCollection extends CollectionName<Schema>> extends UseResourceResult<RowHandle<Schema, TCollection>> {
    row: RowHandle<Schema, TCollection> | undefined;
}
export interface UseCrdtResult<TValue> {
    value: TValue;
    version: number;
    status: "idle" | "connected";
    flush(): Promise<void>;
}
export interface UseHookOptions {
    enabled?: boolean;
}
export interface UseShareLinkHookOptions extends UseHookOptions {
}
export interface OpenedInviteResult<Schema extends DbSchema, TOpened extends AnyRowHandle<Schema> = AnyRowHandle<Schema>> {
    kind: "opened";
    ref: RowRef;
    role: Exclude<MemberRole, "submitter">;
    row: TOpened;
}
export interface JoinedInviteResult {
    kind: "joined";
    ref: RowRef;
    role: "submitter";
}
export type AcceptedInviteResult<Schema extends DbSchema, TOpened extends AnyRowHandle<Schema> = AnyRowHandle<Schema>> = OpenedInviteResult<Schema, TOpened> | JoinedInviteResult;
export interface UseAcceptInviteFromUrlOptions<Schema extends DbSchema, TOpened extends AnyRowHandle<Schema> = AnyRowHandle<Schema>> extends UseHookOptions {
    url?: string | null;
    clearInviteParams?: boolean | ((url: URL) => string);
    onOpen?: (row: TOpened) => void | Promise<void>;
    onResolve?: (result: AcceptedInviteResult<Schema, TOpened>) => void | Promise<void>;
}
[rerun: b16]

Agent

Now I have everything I need. Let me write the final plan:

Agent

Input

{"allowedPrompts":[{"tool":"Bash","prompt":"install npm packages"},{"tool":"Bash","prompt":"run vite dev server"}],"plan":"# Plan: Fitness Studio Booking App\n\n## Context\nBuild a complete, client-si...

Output

User has approved your plan. You can now start coding. Start with updating your todo list if applicable

Your plan has been saved to: /Users/alex/.claude/plans/streamed-cooking-feigenbaum.md
You can refer back to it if needed during implementation.

## Approved Plan (edited by user):
# Plan: Fitness Studio Booking App

## Context
Build a complete, client-side-only fitness studio booking web app on top of Vennbase (Puter-backed auth + data) with no custom backend. The owner creates a studio with a class schedule and shares one link with customers. Customers book classes with instant optimistic updates and see availability in near-real-time. Security is enforced by Vennbase's access model — not client code.

---

## Build setup (install + scaffold)

```bash
npm install react react-dom vite @vitejs/plugin-react typescript @types/react @types/react-dom
```

**Files to create:**

- `package.json` — add scripts (`dev`, `build`, `preview`), react/vite/ts deps
- `tsconfig.json` — `"jsx": "react-jsx"`, `"moduleResolution": "bundler"`, `"noEmit": true`
- `vite.config.ts` — `@vitejs/plugin-react` plugin only
- `index.html` — div#root + `<script type="module" src="/src/main.tsx">`

No Puter CDN script tag needed — Vennbase bundles `@heyputer/puter.js` itself.

---

## Schema (`src/schema.ts`)

```ts
defineSchema({
  studios: collection({
    fields: {
      name: field.string(),
      bookingSubmitterLink: field.string(),   // submitter link to hidden bookingRoots row
      createdAt: field.number().indexKey(),
    },
  }),

  classes: collection({
    in: ["studios"],
    fields: {
      name: field.string(),
      startMs: field.number().indexKey(),
      endMs:   field.number().indexKey(),
      limit:   field.number().indexKey(),     // visible to submitters for slot math
      createdAt: field.number().indexKey(),
    },
  }),

  bookingRoots: collection({             // top-level, owner-only, never shared as viewer
    fields: { createdAt: field.number() },
  }),

  bookings: collection({
    in: ["bookingRoots"],
    fields: {
      classId:    field.string().indexKey(),  // class row .id (string, not ref — submitters can't resolve refs to studios)
      bookedAtMs: field.number().indexKey(),  // tiebreak for convergence
    },
  }),

  myBookings: collection({               // user-scoped — private, for cancel/restore
    in: ["user"],
    fields: {
      classId:    field.string().indexKey(),
      bookingRef: field.ref("bookings").indexKey(),
      status:     field.string().indexKey(), // "active" | "cancelled"
      bookedAtMs: field.number().indexKey(),
    },
  }),
})
```

**Security note:** Only `classId`, `bookedAtMs` are `.indexKey()` on `bookings` — submitters using `select: "indexKeys"` see slot counts and tiebreak values only. `owner`, `ref`, `baseUrl`, and any non-indexKey fields are never included. This is enforced server-side by Vennbase.

---

## Vennbase instance (`src/db.ts`)

```ts
export const db = new Vennbase({ schema, appBaseUrl: window.location.origin });
```

---

## App shell (`src/App.tsx`)

Session gate → `useSession(db)` → show sign-in button if not signed in.

After sign-in, `StudioLoader`:
1. `useSavedRow(db, { key: "studio", collection: "studios" })` — restores studio on repeat visits
2. `useAcceptInviteFromUrl(db, { clearInviteParams: true, onResolve: async (result) => { if (result.kind === "opened") await saved.save(result.row); } })` — handles incoming customer links

**Role detection:**
```ts
const currentUser = useCurrentUser(db);
const isOwner = studio.owner === currentUser.user?.username;
```
`studio.owner` is set server-side on creation — cannot be spoofed by a client.

Show `<OwnerView>` or `<CustomerView>` accordingly. If no studio yet (no saved row, no URL invite), show `<WelcomePage>` where the owner can create a studio.

---

## Owner: create studio (`src/hooks/useCreateStudio.ts`)

Critical: await all three writes before the share link is usable by remote clients.

```ts
const bookingRootReceipt = db.create("bookingRoots", { createdAt: Date.now() });
const bookingRoot = bookingRootReceipt.value;
const submitterLinkReceipt = db.createShareLink(bookingRoot, "submitter");
const studioReceipt = db.create("studios", {
  name,
  bookingSubmitterLink: submitterLinkReceipt.value, // optimistic URL value — valid locally right away
  createdAt: Date.now(),
});
await Promise.all([
  bookingRootReceipt.committed,
  submitterLinkReceipt.committed,
  studioReceipt.committed,
]);
return studioReceipt.value;
```

After creation, save via `saved.save(studio)` and set as current studio.

---

## Owner view (`src/components/OwnerView.tsx`)

**Share link:**
```tsx
const { shareLink } = useShareLink(db, studio, "viewer");
<button onClick={() => navigator.clipboard.writeText(shareLink ?? "")}>Copy customer link</button>
```

**Get bookingRootRef** (owner recovers it idempotently on mount):
```ts
useEffect(() => {
  db.joinInvite(studio.fields.bookingSubmitterLink)
    .then(r => setBookingRootRef(r.ref as RowRef<"bookingRoots">));
}, [studio.id]);
```
The owner gets `role: "editor"` back since they created the row.

**Class list:**
```tsx
const { rows: classes = [] } = useQuery(db, "classes", {
  in: studio, orderBy: "startMs", order: "asc"
});
```

**Booking count per class** (full rows, not index-key, since owner has editor access):
```tsx
const { rows: bookings = [] } = useQuery(db, "bookings", {
  in: bookingRootRef, orderBy: "bookedAtMs"
});
// For each class: bookings.filter(b => b.fields.classId === cls.id).length
```

**Add class form:** `name` (text), `startMs` / `endMs` (datetime-local → `new Date(v).getTime()`), `limit` (number).
```ts
db.create("classes", { name, startMs, endMs, limit, createdAt: Date.now() }, { in: studio });
// Optimistic — no await needed for UI
```

---

## Customer view (`src/components/CustomerView.tsx`)

**Join inbox on mount** (idempotent):
```ts
useEffect(() => {
  db.joinInvite(studio.fields.bookingSubmitterLink)
    .then(r => setBookingRootRef(r.ref as RowRef<"bookingRoots">));
}, [studio.id]);
```

**Classes** (customer has viewer access to studio children):
```tsx
const { rows: classes = [] } = useQuery(db, "classes", {
  in: studio, orderBy: "startMs", order: "asc"
});
```

**Index-key bookings** (submitter access, anonymous sibling visibility):
```tsx
const { rows: bookingProjections = [] } = useQuery(db, "bookings", {
  in: bookingRootRef, select: "indexKeys", orderBy: "bookedAtMs", order: "asc"
});
```

**Own bookings** (for "already booked" detection and cancellation):
```tsx
const { rows: myBookings = [] } = useQuery(db, "myBookings", {
  in: CURRENT_USER, orderBy: "bookedAtMs", order: "desc"
});
```

**Book a class** (optimistic):
```ts
const bookingReceipt = db.create("bookings",
  { classId: cls.id, bookedAtMs: Date.now() },
  { in: bookingRootRef! }
);
db.create("myBookings", {
  classId: cls.id,
  bookingRef: bookingReceipt.value.ref,
  status: "active",
  bookedAtMs: Date.now(),
}, { in: CURRENT_USER });
// Both are optimistic — UI updates immediately
```

**Cancel:**
```ts
db.removeParent(myBooking.fields.bookingRef, bookingRootRef!);
db.update("myBookings", myBooking, { status: "cancelled" });
// Both optimistic
```
The customer *owns* their booking row (they created it), so `removeParent` is permitted.

---

## Slot availability convergence

Pure function, called during render:

```ts
const COOLOFF_MS = 5000;

function getSlotInfo(
  projections: DbIndexKeyProjection<Schema, "bookings">[],
  classId: string,
  limit: number,
  nowMs: number
) {
  const forClass = projections
    .filter(p => p.fields.classId === classId)
    .sort((a, b) => a.fields.bookedAtMs - b.fields.bookedAtMs || (a.id < b.id ? -1 : 1));
  
  const count = forClass.length;
  const latestBookedAt = forClass[count - 1]?.fields.bookedAtMs ?? 0;
  const isPending = nowMs < latestBookedAt + COOLOFF_MS;
  
  return { count, available: Math.max(0, limit - count), isFull: count >= limit, isPending };
}
```

During cooloff: show "Booking..." / grey-out book button. After cooloff: show definitive counts.

---

## Real-time

`useQuery` polls automatically. Owner sees booking count updates within a few seconds. Customer sees other customers' bookings appear via the same index-key polling. No CRDT needed — polling on both sides is sufficient.

---

## File list (creation order)

1. `package.json` (update)
2. `tsconfig.json`
3. `vite.config.ts`
4. `index.html`
5. `src/schema.ts`
6. `src/db.ts`
7. `src/main.tsx`
8. `src/App.tsx`
9. `src/hooks/useCreateStudio.ts`
10. `src/components/OwnerView.tsx`
11. `src/components/CustomerView.tsx`

Keep `WelcomePage` (no-studio state with a create-studio form for owners and a "paste link" field for customers) inline in `App.tsx`.

---

## Styling

Plain HTML elements with inline styles or a minimal style tag in `index.html`. No CSS framework — keep it functional and readable. No emojis.

---

## Verification

1. `npm run dev` — app loads, shows Puter sign-in button
2. Sign in → see "Create studio" form → create → see class schedule
3. Add a class → appears immediately in the list
4. Copy customer link
5. Open link in a private/incognito window → sign in as a different Puter user → see studio name + classes
6. Click Book → slot count decreases immediately (optimistic), owner's view shows +1 booking within seconds
7. Cancel → booking disappears optimistically
8. Owner sees class list real-time updates without refreshing

Agent

Now create tsconfig, vite config, and index.html in parallel:

Agent

That App.tsx has some bad patterns I need to fix before moving on:

Agent

The errors are forward references (components not yet created) and type issues with save. Let me fix App.tsx and then create the remaining files:

Agent

Just a hint, not a blocker. Let me keep building — creating the remaining files:

Agent

Clean. Now start the dev server:

Agent

TypeScript is clean and the dev server is running at http://localhost:5174.

Here's a summary of what was built:

Files created:
- package.json — scripts + all deps
- tsconfig.json, vite.config.ts, index.html — build scaffold
- src/schema.ts — studios, classes, bookingRoots, bookings, myBookings
- src/db.ts — Vennbase instance
- src/main.tsx — React root with VennbaseProvider
- src/App.tsx — session gate, invite handler, role routing, welcome page
- src/hooks/useCreateStudio.ts — creates the hidden booking inbox + studio atomically
- src/components/OwnerView.tsx — class schedule, add-class form, live booking counts, copy-link button
- src/components/CustomerView.tsx — class list, Book/Cancel buttons, slot availability with 5s cooloff convergence

Security model in effect:
- bookingRoots is never shared as a viewer link — customers only get submitter access via the embedded link
- select: "indexKeys" on bookings exposes only classId + bookedAtMs — no owner identity, no refs, enforced server-side by Vennbase
- studio.owner is set server-side on creation and used for role detection — cannot be spoofed

You

<local-command-caveat>Caveat: The messages below were generated by the user while running local commands. DO NOT respond to these messages or otherwise consider them in your response unless the user explicitly asks you to.</local-command-caveat>

You

<command-name>/context</command-name>
<command-message>context</command-message>
<command-args></command-args>

You

Now you've had experience working with Vennbase, I'd like to get your evaluation of the platform in comparison to other options you know. Where did it cause friction?

Focus on the things that slowed you down or wasted tokens, as well as things that contributed to bugs. You may also share what was a positive surprise about the experience.

Keep it brief and don't describe solutions.

Agent

Friction points

Role/ref type cascade. The save() method on useSavedRow takes a RowHandle in one overload and a RowRef in another, but the type error messages span 8 lines of generic noise. I wrote the wrong variant twice before getting it right. Similar issue with removeParent — it accepts RowInput but the error when you pass the wrong thing gives you the full schema union, not a hint about what's actually wrong.

bookingRef field type conflict. field.ref("bookings") creates a typed ref, but submitters can't resolve refs to collections they don't have access to. The schema compiles fine — the problem would only surface at runtime. Nothing in the API surface warns you at definition time that this field will be opaque to submitters.

select: "indexKeys" return type inference. The type system does handle this correctly, but only if you write the options object inline. Extracting query options into a variable loses the literal type and you get RowHandle[] instead of DbIndexKeyProjection[]. This forced me to keep options inline everywhere.

No where clause on non-indexKey fields. The myBookings query needed where: { studioRef: ... } but studioRef had to be .indexKey() for that to work. Easy to miss — silently becomes a full scan if you forget.

What caused the bug I caught

The WelcomePage intermediate component I wrote that called require("react") — a moment of confusion about how to lazily import a hook. Caught it before running but it wasted tokens on a rewrite.

Positive surprise

The blind-inbox pattern is genuinely elegant. Embedding the submitter link as a plain string field on the readable row means customers self-serve their inbox access with one idempotent call, and the owner never has to manage a member list. That's a meaningful reduction in app-level access-control logic compared to anything I'd build on Supabase RLS or Firebase rules. The explicit-grant model also meant I could reason about the security surface in one pass rather than auditing rule expressions.

You

Give a two-sentence summary evaluation: would you want to use Vennbase again?

Agent

Yes — the access control model is the best I've seen for this class of app, and "no backend" is a genuine promise rather than a marketing hedge. The TypeScript ergonomics need polish (generic error messages, inference loss on extracted options), but none of the friction was a blocker and the core abstractions held up under a non-trivial security requirement.